Authenticated Rate Limiting for Application Developers¶
This user guide walks you through an example of how to configure authenticated rate limiting for an application using Kuadrant.
Authenticated rate limiting rate limits the traffic directed to an application based on attributes of the client user, who is authenticated by some authentication method. A few examples of authenticated rate limiting use cases are:
- User A can send up to 50rps ("requests per second"), while User B can send up to 100rps.
- Each user can send up to 20rpm ("request per minute").
- Admin users (members of the 'admin' group) can send up to 100rps, while regular users (non-admins) can send up to 20rpm and no more than 5rps.
In this guide, we will rate limit a sample REST API called Toy Store. In reality, this API is just an echo service that echoes back to the user whatever attributes it gets in the request. The API exposes an endpoint at GET http://api.toystore.com/toy, to mimic an operation of reading toy records.
We will define 2 users of the API, which can send requests to the API at different rates, based on their user IDs. The authentication method used is API key.
| User ID | Rate limit |
|---|---|
| alice | 5rp10s ("5 requests every 10 seconds") |
| bob | 2rp10s ("2 requests every 10 seconds") |
Run the steps ① → ④¶
① Setup¶
This step uses tooling from the Kuadrant Operator component to create a containerized Kubernetes server locally using Kind, where it installs Istio, Kubernetes Gateway API and Kuadrant itself.
Note: In production environment, these steps are usually performed by a cluster operator with administrator privileges over the Kubernetes cluster.
Clone the project:
Setup the environment:
Request an instance of Kuadrant:
kubectl -n kuadrant-system apply -f - <<EOF
apiVersion: kuadrant.io/v1beta1
kind: Kuadrant
metadata:
name: kuadrant
spec: {}
EOF
② Deploy the Toy Store API¶
Create the deployment:
Create a HTTPRoute to route traffic to the service via Istio Ingress Gateway:
kubectl apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
name: toystore
spec:
parentRefs:
- name: istio-ingressgateway
namespace: istio-system
hostnames:
- api.toystore.com
rules:
- matches:
- path:
type: Exact
value: "/toy"
method: GET
backendRefs:
- name: toystore
port: 80
EOF
Export the gateway hostname and port:
export INGRESS_HOST=$(kubectl get gtw istio-ingressgateway -n istio-system -o jsonpath='{.status.addresses[0].value}')
export INGRESS_PORT=$(kubectl get gtw istio-ingressgateway -n istio-system -o jsonpath='{.spec.listeners[?(@.name=="http")].port}')
export GATEWAY_URL=$INGRESS_HOST:$INGRESS_PORT
Verify the route works:
Note: If the command above fails to hit the Toy Store API on your environment, try forwarding requests to the service and accessing over localhost:
③ Enforce authentication on requests to the Toy Store API¶
Create a Kuadrant AuthPolicy to configure the authentication:
kubectl apply -f - <<EOF
apiVersion: kuadrant.io/v1beta2
kind: AuthPolicy
metadata:
name: toystore
spec:
targetRef:
group: gateway.networking.k8s.io
kind: HTTPRoute
name: toystore
rules:
authentication:
"api-key-users":
apiKey:
selector:
matchLabels:
app: toystore
allNamespaces: true
credentials:
authorizationHeader:
prefix: APIKEY
response:
success:
dynamicMetadata:
"identity":
json:
properties:
"userid":
selector: auth.identity.metadata.annotations.secret\.kuadrant\.io/user-id
EOF
Verify the authentication works by sending a request to the Toy Store API without API key:
curl -H 'Host: api.toystore.com' http://$GATEWAY_URL/toy -i
# HTTP/1.1 401 Unauthorized
# www-authenticate: APIKEY realm="api-key-users"
# x-ext-auth-reason: "credential not found"
Create API keys for users alice and bob to authenticate:
Note: Kuadrant stores API keys as Kubernetes Secret resources. User metadata can be stored in the annotations of the resource.
kubectl apply -f - <<EOF
apiVersion: v1
kind: Secret
metadata:
name: bob-key
labels:
authorino.kuadrant.io/managed-by: authorino
app: toystore
annotations:
secret.kuadrant.io/user-id: bob
stringData:
api_key: IAMBOB
type: Opaque
---
apiVersion: v1
kind: Secret
metadata:
name: alice-key
labels:
authorino.kuadrant.io/managed-by: authorino
app: toystore
annotations:
secret.kuadrant.io/user-id: alice
stringData:
api_key: IAMALICE
type: Opaque
EOF
④ Enforce authenticated rate limiting on requests to the Toy Store API¶
Create a Kuadrant RateLimitPolicy to configure rate limiting:
kubectl apply -f - <<EOF
apiVersion: kuadrant.io/v1beta2
kind: RateLimitPolicy
metadata:
name: toystore
spec:
targetRef:
group: gateway.networking.k8s.io
kind: HTTPRoute
name: toystore
limits:
"alice-limit":
rates:
- limit: 5
duration: 10
unit: second
when:
- selector: metadata.filter_metadata.envoy\.filters\.http\.ext_authz.identity.userid
operator: eq
value: alice
"bob-limit":
rates:
- limit: 2
duration: 10
unit: second
when:
- selector: metadata.filter_metadata.envoy\.filters\.http\.ext_authz.identity.userid
operator: eq
value: bob
EOF
Note: It may take a couple of minutes for the RateLimitPolicy to be applied depending on your cluster.
Verify the rate limiting works by sending requests as Alice and Bob.
Up to 5 successful (200 OK) requests every 10 seconds allowed for Alice, then 429 Too Many Requests:
while :; do curl --write-out '%{http_code}\n' --silent --output /dev/null -H 'Authorization: APIKEY IAMALICE' -H 'Host: api.toystore.com' http://$GATEWAY_URL/toy | grep -E --color "\b(429)\b|$"; sleep 1; done
Up to 2 successful (200 OK) requests every 10 seconds allowed for Bob, then 429 Too Many Requests:
while :; do curl --write-out '%{http_code}\n' --silent --output /dev/null -H 'Authorization: APIKEY IAMBOB' -H 'Host: api.toystore.com' http://$GATEWAY_URL/toy | grep -E --color "\b(429)\b|$"; sleep 1; done